1. Field of the Invention
The invention relates to a radiation-sensitive resin composition.
2. Discussion of the Background
When applying deep ultraviolet rays (e.g., KrF excimer laser light or ArF excimer laser light) or the like to a chemically-amplified radiation-sensitive resin composition, an acid is generated in the exposed area, and a difference in solubility rate in a developer occurs between the exposed area and the unexposed area due to chemical reactions catalyzed by the acid. A resist pattern is formed on a substrate by utilizing the difference in solubility rate.
When precisely controlling the line width (e.g., when the device design dimensions are equal to or less than sub-half micrometers), it is important for a chemically-amplified resist to exhibit excellent resolution, show small line width roughness (LWR) (i.e., an index of a variation in line width of a resist pattern), and produce a rectangular pattern. Technology that adds a basic compound as an acid diffusion controller that adjusts the acid diffusion rate has been disclosed in order to control a fine shape (see Japanese Examined Patent Publication (KOKOKU) No. 2-27660 and Japanese Patent Application Publication (KOKAI) No. 2009-53688, for example). An acid diffusion controller that dissociates due to an acid and loses acid diffusion controllability has attracted attention since high contrast between the exposed area and the unexposed area is obtained.